Despite signs of economic growth strengthening, there is little to indicate that will be accompanied by a pick-up in inflation because of still-considerable labor market slack.

Persistently low inflation could complicate matters for the Fed, which is getting ready to start reducing the pace of its monetary stimulus.

Last month, wholesale gasoline prices fell 0.7 percent, accounting for nearly three-quarters of the decrease in the energy index.

Wholesale food prices were flat after rising 0.8 percent in October. Higher prices for pork were offset by a record fall in bakery goods and the biggest drop in the prices for young chickens in nearly three years.